Clamping device for flexible printing plates



1969 P. HEIMLICHER ET AL 3,470,817

CLAMPING DEVICE FOR FLEXIBLE PRINTING PLATES Filed Aug. 22, 1967 2Sheets-Sheet 1 lavvnvrozs PAML HE/MLICHER Rave 8 0 K K Iv fly.-

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CLAMPING DEVICE FOR FLEXIBLE PRINTING PLATES Filed Aug. 22, 1967 2Sheets-Sheet 2 PAm. HE /ML/(HEE Km flux/ 1 WMJM Amalie United StatesPatent 3,470,817 CLAMPING DEVICE FOR FLEXIBLE PRINTING PLATES PaulHeimliclier, Bolligen, and Ren Biirki, Bern, Switzerland, assignors toFallert Winkler & Co. Ltd., Bern, Switzerland Filed Aug. 22, 1967, Ser.No. 662,436 Claims priority, application Sweden, Sept. 5, 1966, 11,944/66 Int. Cl. B41f 27/06 US. Cl. 101-378 Claims ABSTRACT OF THE DISCLOSUREA clamping device for securing flexible printing plates on a rotaryprinting press composed of a clamping saddle and means for securing theflexible printing plate on the saddle. A pair of spaced elongatedgrooves are positioned along the longitudinal edges of the saddle and amovably positionable support member is disposed within each of thegrooves having a support surface directed toward and disposed at anoblique angle to the longitudinal edge. The support surfaces in eachpair of support members along a longitudinal edge are disposed inoppositely sloping directions with respect to the edge. Screw membersare positioned within the saddle attached to the support members forpositioning them along the longitudinal edge of the saddle. A clampingbar extends along the longitudinal edge of the saddle spaced outwardlyfrom the support members. Gripping members are provided on the clampingbar to engage slots or openings in the edge of the flexible plate forholding it in position. Slots are formed in the clamping saddleextending between the support surface of the support members to thelongitudinal edge of the saddle. A support arm extends from the clampingbar through each of the slots into contact with the support member. Thesupport arm has a contacting surface disposed in parallel touchingrelationship with the contacting surface on the support member. Due tothe angular disposition of the support surfaces of the support memberand support arm with respect to the longitudinal edge of the clampingsaddle, when the support members are moved in a direction parallel tothe longitudinal edge the support arms are urged in a direction normalto the longitudinal edge, forcing the clamping bar outwardly forsecuring the flexible printing plate in position on the clamping saddle.Additionally, the support members may be adjusted to exert a diagonalstress on the flexible plate in the event that it is necessary to do soto properly align it on the clamping saddle.

THE PRIOR ART The present invention is directed to a clamping device forsecuring a flexible printing plate on a rotary printing press and, moreparticularly to an arrangement for securing the plate by moving iteither transversely, longitudinally or diagonally with respect to theaxis of the rotary press.

The appearance of thin flexible printing plates, the so-called windingplates, has provided a problem in printing presses which are equipped toreceive the thicker stereotype plates, this has been a particularproblem in relief printing. Merely pasting the plates, as has been knownfor a long time, is not satisfactory because of the difficulty inproperly registering the plate on the printing press. Further, when theplates are removed from the press, the removal operation usually resultsin the destruction of the winding plates.

Though it has been known to use holding devices for securing the thinflexible plates, a workable arrangement has not been achieved to date.One of the problems has ice been the difliculty in obtaining properregistration of the flexible plate on the saddle. In one arrangement agreat number of screws were employed about the periphery of the flexibleplate for securing it to the saddle. While the screws assisted inachieving proper registration, there was the risk that individual screwsmight be tightened too much, the plate would be deformed. Additionally,in such an arrangement the time required for properly securing andaligning the flexible plate was excessive. The devices employed to datehave not taken into account the fact that the sides of the windingplates are not always cut or punched at right angles. Accordingly, insecuring the plates on the printing press, it must be possible toposition one corner outwardly to a greater extent than the others, or,in other words, to dispose the edges in slanting relationship.

In the patent to Strahorn, No. 3,107,610, issued Oct. 22, 1963, anarrangement is shown for securing flexible plates along one edge. A pairof wedging surfaces is employed for forcing a longitudinal edge of theflexible plate into engagement with a catch along the edge. In thisdevice it is not possible to displace the flexible plate diagonally withrespect to the axis of the printing press. While, under normalcondition, a plate can be secured tightly on the saddle, it is notpossible to align it properly in the event the sides of the plate arenot arranged perpendicularly to one another.

SUMMARY OF THE INVENTION It is the primary object of the presentinvention to provide a clamping device for a flexible plate on a rotaryprinting press which permits the plate to be positioned longitudinally,transversely and also diagonally with respect to the axis of rotation ofthe press.

It is an object of the present invention to provide separate membersalong the longitudinal edge of a clamping saddle for individuallypositioning the opposite ends of the edge of a flexible plate to affordany diagonal alignment which might be required.

Another object of the present invention is to provide means forsimultaneously positioning the support members along a longitudinal edgeof the clamping saddle.

Still another object of the invention is to provide contaoting surfaceson the elements which position a flexible plate on a clamping saddle fortranslating a movement parallel to the longitudinal edge of the clampingsaddle into a movement normal to the longitudinal edge.

A further object of the invention is to provide an arrangement forsecuring a flexible plate in position on a clamping saddle which issimple in construction and easy to assemble and to adjust.

Moreover, another object of the invention is to provide a clampingdevice which supplies an improvement over presently known devices forobtaining proper regis tration of flexible printing plates on clampingsaddles, even though the edges of the plates may not be properlydisposed at right angles to each other.

The present invention provides an arrangement not only for tightlysecuring a flexible printing plate to a clamping saddle on a rotaryprinting press, but it also assures the proper registration of the plateon the saddle even if a diagonal displacement of one or both edges ofthe plate is required with respect to the axis of the printing press.Support members are positioned within the clamping saddle with supportsurfaces disposed at an oblique angle to [the longitudinal edge of theclamping saddle. The support surfaces along each longitudinal edge aredisposed in oppositely sloping directions with respect to thelongitudinal edge. Means, such as threaded bolts, are secured to thesupport members and to the clamping saddle for moving the supportmembers in a direction parallel to the longitudinal edge. Spacedoutwardly from the longitudinal edge is a clamping bar having teeth orother gripping means arranged to fit into slots or openings along theedge of the flexible plate and to assist in properly securing the platesin the circumferential direction about the surface of the clampingsaddle. Extending from the clamping bar toward the clamping saddle andinto contact with the support members are support arms each having asupport surface disposed in parallel relationship with the supportsurface on the support member. With the support surfaces of the supportmembers and support arms disposed obliquely with relationship to thelongitudinal edge of the clamping saddle, when the support member ismoved in a direction parallel to the longitudinal edge, the support armis moved in a direction normal to the longitudinal edge and as thesupport arm is forced outwardly from the saddle, the clamping barsecurely grips and holds the flexible plate tightly in position. If adiagonal adjustment is required in the flexible plate, the individualsupport members may be positioned in an unbalanced manner whereby oneend of an edge on the flexible plate is forced outwardly to a greaterextent than the other end to provide the proper registration.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,its operating advantages and specific objects attained by its use,reference should be had to the accompanying drawings and descrip tivematter in which there are illustrated and described preferredembodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 shows an end view of a clamping device for a rotary printingpress incorporating the present invention;

FIG. 2 is a side view of the clamping device shown in FIG. 1;

FIG. 3 is an enlarged partial sectional view taken along line II of FIG.2;

FIG. 4 is an enlarged view of a portion of the clamping device shown inFIG. 2;

FIG. 5 is an enlarged partial sectional view of one end of the clampingdevice as shown in FIG. 1; and

FIG. 6 is a side view of another embodiment of the present inventionviewed from the opposite side of the clamping device to that illustratedin FIG. 2.

DESCRIPTION OF THE INVENTION In the present invention a clamping saddle1 is secured to a printing plate cylinder 2 in a manner similar tosecuring a stereotype printing plate and is secured in position by meansof bevels 3. A flexible printing plate 4 having a pair of longitudinallyextending edges 4A and a pair of transversely or circumferentiallyextending edges 4B is mounted on the clamping saddle 1. Along itslongitudinal edges 4A the flexible printing plate 4 has a plurality ofholes or slots 5 for securing the edge of the plate in position.

Spaced below [the longitudinal edge 4A of the plate 4 is a clamping bar7 which extends in spaced parallel relationship with the adjacentlongitudinal edge A of the clamping saddle 1. Along its upper face theclamping bar 7 has a number of teeth or gripping members 6 arranged toregister with the holes or slots 5 in the flexible printing plate forsecuring the plate in position on the clamping saddle. Two support arms8 extend normally to the clamping bar and fit into slots 9 formed in theclamping saddle, see FIGS. 2 and 3. The width of the support arms 8 isless than the width of the slots affording a certain tolerancepermitting the arms to be moved slightly in the direction of thelongitudinal edge of the clamping saddle.

At the inner end of each slot 9 in the clamping saddle an elongatedgroove 11 extends perpendicularly to the slot and is in parallelrelationship with the longitudinal edge 10A of the clamping saddle. Asupport member 12 is 10- ,cated in each of these grooves and ispositionable along the longitudinal axis of the groove by means of athreaded bolt 14 secured to the saddle and to the support member. Aspring 15 is positioned in each of the grooves at the opposite side ofthe support member from the bolt 14. The spring 15 contacts the supportmember biasing it in the direction of the circumferentially extendingedge 10B of the clamping saddlev The support member 12 has a supportsurface 13 in contact with and in parallel relationship with a supportsurface SA on the support arm 8. These support surfaces 8A, 13 aredisposed obliquely to the longitudinal edge of the clamping saddle, andfurther, each pair of contacting support surfaces along the longitudinaledge, with relationship to the other pair, are disposed in oppositelysloping directions with respect to the longitudinal edge.

In FIG. 6 another embodiment of the means for movably positioning thesupport members 12 is shown wherein a single screw 16 extends throughthe clamping saddle attached to both of the support members 12 along onelongitudinal edge of the clamping saddle so that both of the members canbe positioned simultaneously. This particular arrangement for moving thesupport members facilitates the mounting of the flexible plate on theclamping saddle. The screw 16 is guided in its axial direction by aslide member 17 positioned centrally within a groove 19 along thelongitudinal direction of the clamping saddle. A pair of screws 18extend longitudinally inward from the opposite circumferential edges 10Bof the saddle into contact with the opposite surfaces of the slidemember 17. This arrangement of the slide member 17 and the screws 18 isprovided along each of the longitudinal edges 10A of the clampingsaddle.

Depending on the direction of movement of the screws 18 and thecorresponding movement of the slide member 17 and the screw 16 thelongitudinal edges of the printing plate will assume an obliquedisposition relative to the longitudinal edges of the saddle. Forinstance, in FIG. 6 if the screws 18 are moved to the right, the slide17 and the screws 16 will also move to the right causing the clampingbar 7 and the longitudinal edge of the printing plate attached theretoto be disposed obliquely to the longitudinal edge of the saddle. Ineffect, the clamping bar pivots with its right end moving outwardly fromand its left end moving inwardly toward the longitudinal edge of thesaddle. Conversely, if the screws 18 are moved in the oppositedirection, the clamping bar will pivot through a position where it isparallel to the longitudinal edge of the saddle and then assume anoblique disposition sloping in the opposite direction as the screwscontinue to move through to the left.

In assembling a flexible printing plate 4 in operating position on theprinting press cylinder 2, the holes 5 along the longitudinal edges 4Aof the plate 4 are fitted onto the gripping members 6 along the clampingbar 7. Initially for mounting the flexible plate in position, thesupport members 8 would be located closer to the center of the clampingsaddle so that a certain tolerance is provided in securing the plate.With the plate secured on the gripping members of the clamping bar, thebar can then be disposed outwardly away from the clamping saddle tosecure the flexible mounting plate tightly in position in the clampingsaddle. Before the support members are finally positioned, however, thesprings 15 in the groove force the support members in a position where aslight degree of tension is provided onto the support arms 8 so that theclamping bars are biased outwardly away from the longitudinal edges 10Aof the clamping saddle. In the arrangement shown in FIG. 2, the bolts 14are turned to move the support members 12 in the direction of thecircumferential edges 10B of the saddle. As the support members moveaway from the longitudinal center of the saddle, the oblique dispositionof their surfaces 13 urges the corre sponding support surfaces 8A of thesupport arms 8 in a direction normal to the longitudinal edge of thesaddle A and provides a locking or clamping action as the flexible plateis drawn tightly onto the clamping saddle.

It is preferable in the assembly of the fiexible plate onto the clampingsaddle using the arrangement shown in FIG. 2 to tighten each of thebolts 14 at the same time so that an even tightening effect is achieved.However, if, because of improper registration of the flexible plate onthe clamping saddle, it is desired to dispose it diagonally or at anangular disposition to the axis of the cylinder, one of the bolts wouldbe tightened to a greater degree than the other until the desiredregistration is effected.

While in the drawing the support members are illustrated along only oneof the longitudinal edges, it will be appreciated that a similararrangement may be afforded on the opposite longitudinal edge foreffectively securing and positioning the flexible printing plate inposition.

As indicated previously, if the arrangement shown in FIG. 6 is used fortightening the flexible plate onto the saddle, the movement of screw orbolt 16 operates to position simultaneously both of the support members12 and accordingly the bolts 16 along each of the longitudinal edgeshave the effect of tightening the plate as required.

It will be appreciated that the present invention provides not only aneffective means for properly tightening the flexible plate on a clampingsaddle but also provides for an angular disposition of the flexibleplate with respect to the clamping saddle to take care of anymisregistration which might be present because of the manner in whichthe flexible plate is formed.

What is claimed is:

1. A clamping device for securing a flexible printing plate on a rotaryprinting press comprising a clamping saddle having a pair oflongitudinally extending edges and adapted to receive and support aflexible printing plate, a pair of movably positionable support membersdisposed within said saddle and located in spaced positions along one ofthe longitudinal edges of said saddle, each support member having asupport surface directed outwardly and disposed at an oblique angle tosaid longitudinal edge, each support surface in said pair of supportmembers disposed in an oppositely sloping direction with respect to saidlongitudinal edge, means for moving said support members in a directionparallel with said longitudinal edge, a clamping bar extending alongsaid longitudinal edge of said clamping saddle, a pair of spaced supportarms secured to said clamping bar and each arm extending therefrom intocontacting engagement with one of said support members, each of saidsupport arms having a support surface in contact with the opposedsupport surface on said support member, the support surfaces on saidsupport arm in substantially parallel relationship with the supportsurface of said support member whereby, when the means for positioningsaid support members move said support members in a direction parallelto said longitudinal edge, the support arms are moved in a directionnormal to said longitudinal edge.

2. A clamping device as set forth in claim 1, wherein a pair ofindividual elongated grooves is formed in said clamping saddle and eachgroove is arranged to contain one of said support members, said groovesextending in the direction of the longitudinal edge of said clampingsaddle.

3. A clamping device as set forth in claim 2, wherein a pair of slots isformed in said clamping saddle, each said slot extending from saidlongitudinal edge inwardly to one of said grooves, each of said slotsarranged to receive one of said support arms of said clamping bar.

4. A clamping device as set forth in claim 3, wherein said slot has awidth greater than the width of said support arm whereby said supportarm can be displaced laterally Within said slot.

5. A clamping device as set forth in claim 1, wherein said means formoving said support members comprises a pair of threaded bolts fittedinto said clamping saddle and secured to said support members.

6. A clamping device as set forth in claim 5, wherein a spring member ispositioned within said groove in contact with the surface of said grooveat one end and with the opposite surface of said support member at itsother end for urging said support member into contacting relationshipwith said support arm.

7. A clamping device as set forth in claim 1, wherein a single screwextends through said saddle along and adjacent the longitudinal edgethereof and is secured to both of said support members positioned alongeach said longitudinal edge for simultaneously positioning each of saidsupport members.

8. A clamping device as set forth in claim 7, wherein a slide member isdisposed intermediate the ends of said single screw for guiding it inthe axial direction, and means for displacing said slide member in adirection parallel to the longitudinal edge of said clamping saddle.

9. A clamping device as set forthin claim 1, wherein said clamping baris disposed outwardly from and in substantially parallel relationshipwith the longitudinal edge of said clamping saddle, and gripping membersformed on the upper surface of said clamping bar and adapted to receivethereon openings formed in the edge of a flexible plate for securing theflexible plate in position on said clamping saddle.

10. A clamping device as set forth in claim 1, wherein each of saidsupport arms extends perpendicularly from said clamping bar through oneof said slots in said clamping saddle into contact with one of saidsupport members.

References Cited UNITED STATES PATENTS 2,709,405 5/1955 McWhorter 101378 ROBERT E. PULFREY, Primary Examiner CLIFFORD D. CROWDER, AssistantExaminer US. Cl. X.R. l01415.1

